Free module Social media follow links v2.1.0 does not display the icons correctly

[Yulian]

Hello,
I have the following problem:
I have fill the URL's in the social media follow links module, but some icons like Youtube, RSS and Linkedin is not appear on frontoffice.  If move the mouse cursor over the place where the icon must be the links is activated and work properly, just icon missing, see the attachment. Please for your advice to solve this issue.

Free Social media follow links module v2.1.0
Prestashop v1.7.5.1
Website: https://beauty-vision.eu